Corn header with automatic tensioning of feeder chains

Claim 1

In apparatus for feeding crop material rearwardly and upwardly from a crop gathering head for a combine into the combine, said apparatus comprising, a housing having a floor, top and side walls and adapted to be mounted in inclined relation at the forward end of the combine, said housing being adapted to have its lower end connected in crop receiving relationship with said crop gathering head and its upper end connected in crop delivering relationship with said combine, and a feeder chain conveyor mounted in said housing and having a lower run which is operative to advance the harvested material upwardly along the floor of said housing, said chain conveyor having its upper end mounted on a top shaft assembly, power receiving means on said top shaft assembly for receiving power to drive said conveyor, and said conveyor having its bottom end mounted on an idler shaft assembly; the improvement comprising means mounting said idler shaft assembly for allowing limited movement thereof in a direction toward and from the floor of said housing and means for biasing said idler shaft assembly forwardly toward a downward position, said means for mounting said bottom idler shaft assembly comprising a cross shaft having its ends extending outside of the housing side walls through accommodating apertures therein, bearing members on the ends of said shaft, support arms pivotally mounted exteriorally on said housing side walls, said bearing members being movably mounted on said support arms and resilient means for urging said bearing members in a direction to automatically tension the conveyor chains and to urge said bearing members in the direction of the floor of said housing.